Plate condenser evaporator



June 21, 1966 R. BECKER PLATE CONDENSER EVAPORATOR 8 Sheets-Sheet 1 Filed April 15, 1963 /n yen/or RUDOLF BECKER June 21, 1966 R. BECKER 3,256,704

PLATE CONDENSER EVAPORATOR Filed April 15, 1963 8 Sheets-Sheet 2 B 7 9 24 f I 17 I f g 25 iii;

L 3 lnvenfor RUQOLF BECKER June 21, 1966 R. BECKER 3,256,704

PLATE CONDENSER EVAPORATOR Filed April 15, 1963 8 Sheets-Sheet 3 i 7 I u n l0 RUDOLF BECKER m mw June 21, 1966 R. BECKER PLATE CONDENSER EVAPORATOR 8 Sheets-Sheet 5 Filed April 1.5, 1963 M van for 29 43 35 RUDOLF BECKER A/fomcvs June 21, 1966 Filed April 15, 1963 R. BECKER PLATE CONDENSER EVAPORATOR 8 Sheets-Sheet 6 I Fig. 11

In venfor RUDQLF BECKER Aaamew June 21, 1966 R. BECKER 3,256,704

PLATE CONDENSER EVAPORATOR Filed April 15, 1963 8 Sheets-Sheet '7 Fig. 15

/n venf 56 a. f 75 RUDOLF BECKER A/fomeys June 21, 1966 R. BECKER PLATE CONDENSER EVAPORATOR 8 Sheets-Sheet 8 Filed April 15, 1963 ln van/or RUDOLF EEC/(ER United States Patent 3,256,704 PLATE CONDENSER EVAPORATOR Rudolf Becker, Munich-Solln, Germany, assignor to Gesellschaft fur Lindes Eismaschinen Aktiengesellschaft, Munich, Germany Filed Apr. 15, 1963, Ser. No. 272,977 Claims priority, application Germany, Apr. 21, 1962, G 34,798 8 Claims. (Cl. 62-42) The present invention relates to a condenser evaporator especially adapted for gas and air fractionation, more particularly, to a condenser evaporator having vertical separating plates with corrugated metal inserts between said plates so as to form a rigid assembly therewith, the gas to be condensed being passed downwardly through the assembly and the liquid to be evaporated being passed upwardly through the assembly.

Various forms of plate condensers have been previously constructed. In the conventional plate condenser the assembly of vertical separating plates with corrugated inserts therebetween has a vertical dimension which is greater than its horizontal dimension. One disadvantage of such a construction is that the bubbles of gas in an evaporating liquid must flow upwardly through a considerable height of liquid before reaching the top surface thereof and be liberated. Accordingly, the formation of these gaseous bubbles in the lower portions of the liquid will be suppressed and the temperature of the liquid will increase. This decreases the heat absorption from the condensing vapor to such an extent as to seriously lower the performance and efficiency of the condenser.

Another disadvantage of known forms of plate condensers is that the flow of the liquid being evaporated is very slow particularly in the lower portions of the condenser where no gas bubbles are produced.

It is, therefore, the principal object of the present invention to provide a novel and improved form of a plate condenser evaporator.

It is another object of the present invention to provide a plate condenser evaporator whose performance is considerably increased over that of known condenser evaporators.

It is a further object of the present invention to pro vide a plate condenser evaporator having improved circulation of the liquid therethrough.

The plate condenser evaporator of the present inven tion comprises an assembly of spaced apart vertical separating plates having corrugated metal inserts in the spaces between the plates.

In this assembly the corrugated inserts are positioned so that the corrugations extend vertically and the assembly is enclosed surrounded by an enclosure in such manner as to define spaces at the top and bottom of the assembly. Overflow openings are provided in the side walls of the enclosure along the upper end of the assembly and these overflow openings are connected by a conduit to the inlet opening for the liquid to be evaporated. An outlet is provided in the enclosure for exhausting the evaporated material. With this construction, not only is the entire heating surface of the evaporator submerged in liquid, but also the liquid which is to be evaporated is actively agitated during its upward flow through the corrugated inserts. The gaseous bubbles will then have an optimum distribution over the heated surface and accordingly va-ri ous undesirable deposits will be avoided.

The corrugated metal inserts that receive the liquid from the supply conduit have corrugations sloping up wardly therefrom, whereas the corrugations communicat ing with the supply conduits for the gases to be condensed slope downwardly. Vertically extending metal corrugations are then located in the spaces between the Patented June 21, 1966 separating plates communicating with the upper edges of the upwardly sloping corrugations and with the lower edges of the downwardly sloping corrugations.

Various forms of collector troughs may be mounted on the bottom wall of the enclosure or on the lower por tions of the end walls of the enclosure for collecting the condensate.

It has been found to be particularly advantageous to use corrugated metal inserts which are uniformly perforated over their surfaces. This will permit the gases and liquids to pass transversely over the entire width of the assembly and accordingly will eliminate any dead spots and the resulting accumulation of deposits.

In those cases where condensation occurs, it has been found advantageous to use corrugated metal inserts wherein the corrugations are substantially rectangular and the inserts have transversely extending offset portions along the corrugations. With this construction the flat crests of the corrugations are attached to the vertical separating plates.

Other objects'and advantages of the present invention will be apparent upon reference to the accompanying description taken in conjunction with the following drawings wherein:

FIGURE 1 is a perspective view of the condenser evaporator of the present invention with one end wall being partially removed;

7 and the other portion of the view being taken along the line IVIV of FIGURE 7;

FIGURE 5 is a longitudinal sectional view of the modified condenser evaporator and taken along the line V-V of FIGURE 4;

FIGURE 6 is also a transverse sectional view of the modified condense-r evaporator taken along the line VI- VI of FIGURE 4;

FIGURE 7 is a top plan view of the modified condenser evaporator shown in FIGURE 4, with a portion of the enclosure removed;

FIGURE 8 is a longitudinal sectional view similar to that of FIGURE 5, but showing a further modification;

FIGURE 9 is a longitudinal sectional view similar to that of FIGURE 6 and also showing a further modificaion;

FIGURE 10 is a vertical sectional view taken along the 11116 X'X of FIGURE 11, and showing a particular adaptation of the condenser evaporator of the present Invention;

FIGURE 11 is a top plan view of a condenser evaporator according to the present invention within a two-stage rectification column of an air fractionation apparatus with portions of the assembly enclosures being removed;

FIGURES 12-14 are perspective views showing various forms of corrugated metal inserts employed in the condenser evaporator of the present invention;

FIGURE 15 is a vertical sectional view of still another modification taken along the line XV-XV of FIG- URE 16;

FIGURE 16 is a horizontal sectional view of the installation shown in FIGURE 15 and FIGURE 17 is a vertical sectional view taken through the installation of FIGURES 15 and 16, but showing the condenser evaporator in side elevational view.

With reference to the drawings wherein like reference symbols indicate the same parts throughout the various views, a specific embodiment and several modifications of the invention will next be described in detail. With particular reference to FIGURES 1 through 3 there is illustrated a plate condenser evaporator which comprises a plurality of spaced vertical separating plates 1 of sheet metal with corrugated metal inserts 2 having vertically extending corrugations disposed in the alternating spaces 2a and 2b formed between the separating plates or partitions 1. The corrugated inserts 2 are secured to the vertical separating plates 1 in such a manner as to form a rigid assembly, indicated generally at 3, of separating plates or partitions and corrugated metal inserts.

The assembly 3 is housed within a sheet-metal enclosure 4 having side walls 5, end walls 6, a top wall 7 spaced from the top of the assembly so as to define a space thereabove, and a bottom wall 8 similarly spaced from the bottom of the assembly 3 so as to define a space therebencath. The top wall 7 essentially constitutes a hood for collecting vapors formed by the evaporating process and is provided with overflow slots 9 positioned at the upper edges of the assembly 3. The overflow slots 9 are disposed on both sides of the enclosure and are covered by an overflow collecting trough or conduit 10 which collects the unevaporated overflow liquid. There is an outlet 11 in the top wall 7 for exhausting the vapors therefrom.

On both end walls 6 (FIGS. 2 and 3) of the enclosure 4 at the upper portions of the assembly 3 there are transversely extending supply troughs 12 first ducts into which the gases or vapors which are to be condensed, indicated as A, are supplied. The liquid which is to be evaporated, indicated as B, is introduced into the bottom portions of the assembly 3 through similarly positioned transverse supply troughs 13 second ducts. The liquid B is introduced through supply conduit 14 which leads into branch conduits 15 (FIG. 1) which in turn are connected to the supply troughs 13 through conduits 16. The overflow troughs 10 are connected by conduits 17 to the liquid supply conduits 16 so that the overflow liquids may be introduced into the liquid supply troughs 13 and recirculated.

The gases A that'are to be condensed are introduced into the supply troughs 12 through gas supply lines 18.

Positioned in the alternating spaces 2a between certain of the vertical separating plates 1, and communicating with the top edges of the vertically extending corrugated inserts 2 in the spaces 2a, there are positioned corrugated metal inserts 19 which connecting first corrugated metal plates, as may be seen in FIGURE 2, are downwardly sloping with respect to the supply troughs 12. Each of the corrugated inserts 19 has its upper edges covered by metal strips 20 (see FIG. 4) while the downwardly flowing condensate, as indicated by the arrows in FIGURE 2, is discharged freely down through the vertically corrugated inserts 2 in the spaces 2a into a sump defined by the bottom wall 8 of the enclosure. The condensate can then be discharged through a connection 21 for utilization elsewhere.

As may be seen in FIGURE 3, there are positioned upwardly sloping corrugated metal inserts 22 constituting second corrugated metal plates in the spaces 2b between the separating plates 1. The ends of the sloping inserts 22 communicate with the liquid supply troughs 13. These upwardly sloping metal inserts 22 also communicate with the bottoms of the vertically extending corrugated inserts 2 located in the spaces 2b, as may also be seen in FIG- URES 1 and 3. The lower edges of the upwardly sloping inserts 22 are covered by metal strips 23. Accordingly, the upwardly flowing vapors, as indicated by the arrows in FIGURE 3, pass into the duct means constituted in part by hood 24 defined by the top wall 7 of the enclosure, and are exhausted at 11. Any overflow of the liquid from the corrugated inserts in the spaces 2b will flow through the overflow slots 9 into the conduits 17 to be returned to the liquid-supply troughs 13.

The corrugated metal inserts having the vertically extending corrugations are uniformly perforated so that about 10% of the surface area of these inserts is perforated. The sloping metal inserts 19 and 22 have about 23% of their area uniformly perforated.

As can be seen in FIGURE-2, the length L of the heat exchanger assembly is at least equal to the height of the assembly and is preferably considerably greater (by about 50%) than the height H of this assembly. The maximum height of the assembly is about 1 meter and preferably between 400600 mm.

The width of the spaces 2a and 2b between the vertical separating plates 1 ranges from 8 to 12 mm. depending upon the total size of the structures so that in a plate condenser evaporator there will generally be about vertical separating plates.

The perforated vertical corrugated inserts 2 are clearly illustrated in FIGURE 12. The vertically extending inserts 2, particularly those which are to receive the gas to be condensed, can be improved by using corrugated inserts such as illustrated in FIGURE 13. These inserts have substantially rectangular corrugations with there being transverse offset portions along each of the corrugations.

These corrugated inserts can also be formed, as shown in FIGURE 14, wherein the insert is also longitudinally sinuous or corrugated perpendicularly with respect to the vertically extending corrugations.

It is to be understood that for the condensation or evaporation of specific materials other variations in these corrugated inserts could be employed and the precise shape of the corrugated inserts will depend upon the output of the apparatus and the absence of undesirable deposits within the teat exchanger assembly.

The heat-exchangtr assembly 3 of this invention is constructed of aluminum corrugated inserts and aluminum separating plates, with a low melting point solder being rolled upon both sides of the separating plates. The heat exchanger assembly 3 is first loosely assembled in position and then immersed under pressure in a salt bath whose temperature is kept at exactly the melting point of the solder which is so low that this temperature will never be dangerously close to the melting point of the aluminum inserts and plates. In this manner the heat exchanger assembly can be formed into a rigid unit which will be able to withstand large pressure differences ranging from 5 to 50 atmospheres. Not only will the assembly be able to withstand these pressures between its components but also against the atmosphere. The various conduit connections and hoods are provided with suitable curvatures so that these elements can similarly stand high pressures. After the assembly process has been completed, extreme care is taken to completely remove all the salt from the assembly so as to avoid any subsequent corrosion of the corrugated inserts or separating plates.

Proceeding next to FIGURES 4 through 7, there is illustrated a modification of this invention wherein the gases to be condensed are introduced into the condenser evaporator through the upper portions of the end walls while the condensate with perhaps some residual gas is removed from openings in the bottom wall with additional openings being provided in the bottom wall of the enclosure for admitting the liquid which is to be evaporated. This modification also comprises the downwardly and upwardly sloping corrugated metal inserts and the vertically corrugated inserts between the vertical separating plates previously described.

The gases B which are to be condensed are supplied to the supply troughs 12 through elbows 26. On the bottom of the enclosure there are provided the duct means.

constituted in part by condensate-collector troughs 27, 28 and 29, connected at 27a, 28a and 29a, to a condensatecollector conduit 30. These condensate collector troughs 27 through 29 extend transversely of the heat exchanger assembly and communicate with the bottoms of the vertically extending corrugated inserts located in the spaces 2a.

- consumption by the compressors.

The liquid B that is to be evaporated is introduced into the condenser evaporator through a liquid supply conduit 31 and then through branch conduits 32a through 35a to transversely extending troughs 3235 of the second ducts. The overflow liquid accumulating in the overflow troughs is returned through conduits 36 to the liquid supply conduit 31.

In view of the enclosure bottom structure of this modification, as may be seen in FIGURE 5, the spaces 2a in which the gases A are condensed, are provided in their lower portions with corrugated metal inserts 37 which are sloped downwardly to direct the condensate with possibly some residual gas into the condensate collector troughs 27, 28 and 29. The bottoms of the sloping corrugated inserts 37 are covered with metal strips 38. However, immediately above the collector troughs 2729 the corrugated inserts have vertically extending corrugations up to the sloping corrugated inserts 19.

As may be seen in FIGURE 6, the spaces 2b between the separating plates 1, wherein the liquid B is evaporated,

has positioned in its lower portions corrugated metal inserts 39 which are positioned over the condensatecollector troughs 27-29 and which are sloped upwardly. In a similar manner, metal strips 40 are provided on the bottom edges of the upwardly sloping corrugated inserts 39 so as to close off the collector troughs from the liquid to be evaporated.

As may be seen in FIGURES 8 and 9, some or all of the perforated and corrugated sloping metal inserts, indicated at 19, 37 and 39, can be replaced by corrugated inserts having horizontally extending corrugations indicated at 41, 42 and 43, respectively.

' The plate condenser evaporator of the present invention is particularly suitable for the evaporation of oxygen by the condensation of nitrogen in air fractionation apparatus in which the temperature must be accurately controlled to within 13 C. in order to obtain a minimum power Accordingly, installations of this condensing evaporator can be mounted in a two-stage rectification column as can be seen in FIG- URES 10 and 11.

With particular reference to FIGURE 10, there is shown the upper portion of a higher pressure column 44 and the lower portion of a lower pressure column 45. The condenser evaporator comprises four heat exchanger assemblies 46 which are mounted in the sump 47 of the low pressure column 45 in an oxygen bath. The arrangement of the heat exchangers assemblies 46 is clearly shown in plan in FIGURE 11. It will be readily apparent that the combined lengths of the four heat exchangers assemblies 46 will be considerably greater than the height H of the heat-exchanger installation.

The pressure column 44 is provided with a centrally disposed conduit 48 for the admission of the gases which are to be condensed. This conduit 48 leads upwardly to collector troughs 49 opening to the upper portions of the spaces 2a between the vertical separating plates. These spaces 2a are connected below to collector conduits 50 which in turn are connected to discharge conduits 51 for conveying the condensed nitrogen.

The inner end walls 52 and the outer end walls 53 of the heat exchanger assemblies 46 are closed off by end plates so that the liquid oxygen in the intermediate space 2b must rise vertically. The formation of the gas bubbles in the rising oxygen will cause the assemblies to function as a thermosiphon and thus produce a circulation throughout the oxygen bath located in the sump 47.

The gaseous oxygen will thus escape to the top of the heat exchanger assemblies in the low pressure. column 45 and the liquid oxygen will descend downwardly into the sump. The level of the liquid oxygen is kept at such a height that the entire heat exchanging surface is immersed in liquid so as to establish an active circulation throughout the oxygen bath.

FIGURES through 17 show a further modification of an installation of plate condenser evaporators according to this invention, for obtaining particularly high yields in a two-stage rectification column employed in air fractionation. In such a two-stage rectification column having a lower high pressure stage and an upper low pressure stage, wherein the nitrogen flowing from the high pressure stage condenses while the liquid oxygen that has collected in the sump of the low pressure stage must be evaporated, it is important to accommodate the plate condenser evaporator within the cross-sectional area of the rectification column and to construct the column for a maximum output. The present installation therefore vertically arranges two pairs of heat exchanger assemblies 54 and 55 side-by-side, as may be seen in FIGURE '16. Each heat exchanger assembly has its own independent overflow for liquid oxygen. Liquid oxygen is provided from one or more overflow collectors positioned in the upper low pressure stage through pipes 56 which are inserted into stand pipes 57. Stand pipes 57 are connected through conduits 58 to troughs 59 on the bottom walls of the assemblies 55. The liquid oxygen circulates upwardly in the intermediate spaces 2b in the assemblies 55 while these assemblies function as thermosiphons. Gaseous oxygen is liberated from the top surfaces of the assemblies 55, as indicated at 60, while liquid oxygen flows freely over the upper edges 61 of the assemblies and accumulates in the sump 62 of the low pressure stage.

The level of the liquid oxygen is preferably kept at about the level X shown in FIGURE 17, but can fluctuate between the levels Y and Z so as to permit considerable variations in the output of the installation.

When the liquid oxygen level rises above the level X, there will occur an automatic throttling of the rectification column because the bubbles of gas forming in a lowe-r'portion of the column will have a greater hydrostatic head to overcome and there will also be a smaller difference in temperature between the nitrogen and the oxygen. From its lowest level corresponding to maximum yield, the level of the liquid oxygen will rapidly rise to the normal level so that each assembly will remain under optimal operating conditions and a maximum temperature difference between nitrogen and oxygen will be maintained.

The gaseous nitrogen A from the lower stage flows upwardly through the conduits 63 and then laterally through branch conduits 64 into the supply troughs ,12 which communicate with spaces 2a between the separatingplates of the condenser evaporator shown in the left half of FIGURE 15. The condensed nitrogen A accumulates in the centrally located collector troughs 65 and is returned to the pressure column through conduit Y66 and branch conduits 67. The corrugated metal inserts are constructed in the manner as illustrated in FIGS. 8 and 9.

It is thus apparent that the two lower heat exchanger assemblies 54 are immersed in the liquid in such a manner that they function as thermosiphons to establish a circulation of the liquid through the evaporator.

Thus, it can be seen that the present invention provides a vastly improved plate condenser evaporator which operates more efliciently and is particularly adapted for installation in two-stage rectification columns such as employed in the fractionation of air.

It will be understood that this invention is susceptible to modification in order to adapt it to difi'erent usages and conditions and, accordingly, it is desired to comprehend such modifications within this invention as may fall within the scope of the appended claims.

What is claimed is:

1. A plate condenser evaporator particularly adapted for gas fractionation, said evaporator comprising an enclosure having top, bottom, side, and end walls; a plurality of spaced vertical plates mounted within said enclosure, an end wall of said enclosure being provided with an opening through which gases to be condensed are supplied, first openings being provided in the bottom wall of said enclosure for supplying liquids to be condensed, second openings being provided in the bottom wall of said enclosure for collecting condensate; collector troughs on said enclosure bottom wall communicating with said first and second openings respectively; corrugated metal inserts between certain of said spaced vertical plates and communicating with said gas-supply opening and said condensate collecting openings with one end being lower than the other end so that said corrugated inserts slope downwardly, corrugated metal inserts communicating with said liquid supply openings and upwardly sloping with respect to said liquid supply openings; and vertically corrugated metal inserts between said vertical separating plates and communicating with the respective sloping inserts.

2. The plate condenser evaporator of claim 1, wherein said corrugated metal inserts have uniformly perforated surfaces.

3. A plate condenser-evaporator as defined in claim 1, wherein the vertical height of the space between said plates is at most about 1 meter and the horizontal length of said spaces is on the order of 50% greater than said height.

4. In a plate condenser-evaporator having housing means forming an enclosure, a multiplicity of spacedapart vertical metal partitions in said enclosure defining between them a plurality of chambers, and respective corrugated metal inserts in said chambers bonded to the partitions defining same and having horizontally offset vertical corrugations forming fluid channels within said chambers, the improvement which comprises:

(a) a first duct on said housing means and above said inserts for supplying a gas to be condensed to said enclosure;

(b) a second duct on said housing means below said inserts for supplying a liquid to be evaporated to said enclosure;

(c) first corrugated metal plates in at least some of said chambers between the partitions thereof and having inclined corrugations extending between said first duct and the respective inserts for delivering said gas to the channels thereof;

(d) second corrugated metal plates in others of said chambers between the partitions thereof and having inclined corrugations extending between said first duct and the respective inserts for delivering said liquid to the channels thereof; and

(e) duct means in said housing means above and below said chambers and communicating respectively with said some of said chambers and with said others of said chambers for respectively collecting condensate of said gas and vapors of said liquid,

said chambers having a horizontal length in excess of the vertical height of said chambers.

5. In a plate condenser-evaporator having housing means forming an enclosure, a multiplicity of spacedapart vertical metal partitions in said enclosure defining between them a plurality of chambers, and respective corrugated metal inserts in said chambers bonded to the partitions defining same and having horizontally otfset vertical corrugations forming fluid channels within said chambers, the improvement which comprises:

(a) a first duct on said housing means and above said inserts for supplying a gas to be condensed to said enclosure;

(b) a second duct on said housing means below said inserts for supplying a liquid to be evaporated to said enclosure;

(c) first corrugated metal plates in at least some of said chambers between the partitions thereof and having inclined corrugations extending between said first duct and the respective inserts for delivering said gas to the channels thereof;

(d) second corrugated metal plates in others of said chambers between the partitions thereof and having inclined corrugations extending between said first duct and the respective inserts for delivering said liquid to the channels thereof;

(e) duct means in said housing means above and below said chambers and communicating respectively with said some of said chambers and with said others of said chambers for respectively collecting condensate of said gas and vapors of said liquid; and

(-f) overflow means in said housing means above said chambers and communicating with said second duct for returning liquid overflowing from said others of said chambers to said second duct;

said chambers having a horizontal length in excess of the vertical height of said chambers.

6. The improvement defined in claim 5 wherein said chambers have a maximum height of substantially one meter and said horizontal length of said chambers is substantially 50% greater than said height, said partitions being spaced apart by a distance ranging between substantially 8 and 12 mm., said inserts each being provided with a multiplicity of surface discontinuities along said channels.

7. The improvement defined in claim 6 wherein said surface discontinuities are perforations uniformly provided in said inserts, said first and second corrugated metal plates being uniformly provided within the respective chambers.

8. The improvement defining claim 6 wherein said surface discontinuities are formed by laterally offset portions vertically spaced along the corrugations of said inserts.

References Cited by the Examiner UNITED STATES PATENTS 815,544 3/1906 Linde 62--44 2,571,631 10/1951 Trumpler 165166 2,610,038 9/1952 Phillips 165-166 X 2,663,170 12/1953 Gloyer 165166 2,782,009 2/1957 Rippingille l65166 FOREIGN PATENTS 611,718 7/1958 Italy.

NORMAN YUDKOFF, Primary Examiner. 

1. A PLATE CONDENSER EVAPORATOR PARTICULARLY ADAPTED FOR GAS FRACTIONATION, SAID EVAPORATOR COMPRISING AN ENCLOSURE HAVING TOP, BOTTOM, SIDE, AND END WALLS; A PLURALITY OF SPACED VERTICAL PLATES MOUNTED WITHIN SAID ENCLOSURE, AN END WALL OF SAID ENCLOSURE BEING PROVIDED WITH AN OPENING THROUGH WHICH GASES TO BE CONDENSED ARE SUPPLIED, FIRST OPENINGS BEING PROVIDED IN THE BOTTOM WALL OF SAID ENCLOSURE FOR SUPPLYING LIQUIDS TO BE CONDENSED, SECOND OPENINGS BEING PROVIDED IN THE BOTTOM WALL OF SAID ENCLOSURE FOR SUPPLYING CONDENSATE; COLLECTOR TROUGHS ON SAID ENCLOSURE BOTTOM WALL COMMUNICATING WITH SAID FIRST AND SECOND OPENINGS RESPECTIVELY; CORRUGATED METAL INSERTS BETWEEN CERTAIN OF SAID SPACED VERTICAL PLATES AND COMMUNICATING WITH SAID GAS-SUPPLY OPENING AND SAID CONDENSATE COLLECTING OPENINGS WITH ONE END BEING LOWER THAN THE OTHER END SO THAT SAID CORRUGATED INSERTS SLOPE DOWNWARDLY, CORRUGATED METAL INSERTS COMMUNICATING WITH SAID LIQUIDS SUPPLY OPENINGS AND UPWARDLY SLOPING WITH RESPECT TO SAID LIQUID SUPPLY OPENING; AND VERTICALLY CORRUGATED METAL INSERTS BETWEEN SAID VERTICAL SEPARATING PLATES AND COMMUNICATING WITH THE RESPECTIVE SLOPING INSERTS. 